Abstract: Unsteady
flow line integral convolution (UFLIC) is a texture synthesis technique
for visualizing unsteady flows with high temporal-spatial coherence. Unfortunately
UFLIC requires considerable time to generate each frame due to the huge
amount of pathline integration that is computed for particle value scattering.
This paper presents Accelerated UFLIC (AUFLIC) for near interactive (1
frame/second) visualization with 160,000 particles per frame. AUFLIC reuses
pathlines in the value scattering process to reduce computationally expensive
pathline integration. A flow-driven seeding strategy is employed to distribute
seeds such that only a few of them need pathline integration while most
seeds are placed along the pathlines advected at earlier times by other
seeds upstream and therefore the known pathlines can be reused for fast
value scattering. To maintain a dense scattering coverage to convey high
temporal-spatial coherence while keeping the expense of pathline integration
low, a dynamic seeding controller is designed to decide whether to advect,
copy, or reuse a pathline. At a negligible memory cost, AUFLIC is 9* times
faster than UFLIC with comparable image quality.

8.60X speedup was obtained for a
576x291 time-varying flow( 41 time
steps) and
9.45X speedup was obtained for a 397x397 time-varying
flow(101 time steps)
on an SGI Onyx2 with four 400MHZ MIPS R12000 processors and 4GB memory.Later,
13.05X speedup was obtained for the former flow and
14.13X speedup was obtained for the latter flow
on an HP-Compaq Presario laptop with a single Intel Celeron 1.6GHz
CPU and 512MB SDRAM memory (Windows XP Home).